Fats, frying, and emulsions (1/16) Flashcards
How do people get the fat?
added by itself, or a part of the ingredient
What are examples of invisible fat?
meat, poultry, dairy, eggs, nuts, seeds, avocado, coconut
What are examples of visible fat?
vegetable oils, margarine, butter, lard, tallow, shortening, cocoa butter, and mango seed butter
What are oils?
liquid fats, except for coconut oil and palm kernel oil which is solid
T/F: you need fat to survive
true
What fatty acids can humans not make?
omega-6 (linoleic) and omega-3 (linolenic)
What does fat ensure?
we can absorb certain nutrients
What are fat soluble things?
vitamins A, D, E and K and carotenoids (beta-carotenel)
How does fat flavor?
through taste, color, texture, and odor
Is the melting point higher for fats or oils?
higher
What is the smoke point?
temperature at which it starts smoking
is a higher or lower smoke point better for frying?
higher smoke point
What are “plastic” fats?
appear solid at room temperature and can be molded or pressed into shapes without breaking
What are the different aromas of fat?
butter, sesame oil, olive oil, fish oil
T/F: the oil you cook in can influence the flavor of the final food
true
Why are fats processed?
to refine them and to change their solid/liquid properties
How can liquid oils change to plastic fat?
by using hydrogenation, but this makes trans fat
What are the advantages of hydrogenated oils?
neutral flavor, higher smoke point, resist oxidation, solid
What is the hydrogenation process?
hydrogen gas bubbled through liquid oil in presence of nickel catalyst. The double bonds break and hydrogen is added. fat then becomes more saturated
What are the different methods to produce hydrogenated fats with reduction in trans fats?
interestification and fractionalization
What is interestification?
move the fatty acids around
What is fractionalization?
cut out some of the fatty acids
Where are vegetable oils obtained from?
fruits, seeds, and nuts
How are oils removed?
by pressing or use of solvents to increase extraction
What type of oils remain liquid when refrigerated?
winterized oils (salad oils)
What are the different types of oils/fats?
soybean, cottonseed, olive, canola, sunflower, safflower, peanut, corn, tropical oils (palm, palm kernel, coconut), butter, lard, tallow
What is butter?
milk fat, separated from cream with agitation
What is a dispersed phase in an emulsion?
the little droplets
What is a continuous phase in an emulsion?
the stuff the droplets are floating around in
What are the different types of butter?
sweet, cultured, clarified, salted, unsalted
What is rancid fat?
fat that is breaking down and it is stinky
What is hydrolytic rancidity?
breaking of chemical bonds that causes undesirable odors and flavors in short chain fatty acids such as found in butter
What is oxidative rancidity?
a self perpetuating chain reaction that occurs when fat exposed to heat, light, iron, or copper. can also be caused by certain enzmes
How can you prevent rancidity?
by storing properly and adding antioxidants
What are different types of antioxidants?
nutrients (vit C, vit E, and beta carotene) and synthetic (BHA, BHT, TBHQ, and propyl gallate)
What is frying?
the process of dehydrating the food and cooking it
What is panfry?
some fat/oil in a pan, but doesn’t completely cover the food
What is deep fry?
submerge the food in hot fat/oil
T/F: when frying temperature does not matter
false, if too hot then food will be too dark/burnt on the outside and uncooked on the inside and if too cold the food will absorb extra fat and be greasy/not crisp
What are the best fats for frying?
stable at higher temperatures and have high smoke points
How can you make fat for frying last?
filter the oil, don’t fry things with lots of ice crystals on them, replace the fat when it gets dark, foamy, or starts to smoke
What are some considerations when reducing/replacing fats?
choose leaner meats, use lower fat cooking method, replace fat with “fat replacer”
What are good examples of fat replacers?
carbohydrates, specific compounds designed by food industry (protein based and fat based), and the type of fat (such as saturated with unsaturated)
What are the two different types of emulsions?
fat in water and water in fat
What is a stable emulsion?
its permanent so it stays well mixed (droplets don’t come together)
What is a unstable emulsion?
temporary so it doesn’t stay well mixed (droplets do come together)
What is added to emulsions to help them stay stable?
emulsifiers
What are examples of emulsifiers?
many egg proteins, milk proteins, and soy lecithin
